Polycarbonate resins are generally produced from starting materials induced from petroleum resources. In recent years, however, there is a fear about depletion of petroleum resources, and it is desired to supply a polycarbonate produced from a starting material obtained from biomass resources such as plants. Furthermore, in view of the fact that the global warming caused by increases in carbon dioxide emission and by accumulation thereof brings about climate changes, etc., there is a need for the development of a polycarbonate resin which is produced using a plant-derived monomer as a starting material and which, even when discarded after use, is carbon-neutral.
For example, a technique has been proposed in which isosorbide is used as a plant-derived monomer to obtain a polycarbonate resin through a transesterification reaction with diphenyl carbonate (see, for example, patent document 1).
Meanwhile, since polycarbonate resins produced from starting materials including isosorbide have high transparency, a low photoelastic coefficient, and heat resistance, it has been proposed to use the polycarbonate resins in optical applications such as the retardation plates and substrates of liquid-crystal display devices (see patent document 2). Also disclosed is a polycarbonate resin which has been produced from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and isosorbide and which has a low photoelastic coefficient and excellent heat resistance and moldability and is suitable for use in optical applications (see patent document 3). Furthermore, a film formed from a polycarbonate resin which contains isosorbide and biscresolfluorene has also been disclosed, and it is disclosed that a retardation film formed from this polycarbonate resin not only has a low photoelastic coefficient but also shows reverse wavelength-dispersive characteristics, in which the phase retardation decreases as the wavelength decreases (see patent document 4).